1. Field of the Invention
This invention relates to the field of storage and dispensing vessels, and more particularly to apparatus for storing and dispensing materials under pressure.
2. Description of Related Art
Materials such as soft drink syrup are often stored in and dispensed from vessels which are pressurized to facilitate dispensing. These vessels often comprise a tank having an opening over which a lid can be secured. Before shipping, the material is initially placed in the tank through the opening when the tank is unpressurized. The lid is then placed over the opening so that the material remains in the tank throughout shipping. When the material is to be dispensed, the tank is pressurized by introducing a gas such as carbon dioxide into the tank. The increase in pressure inside the tank causes the material to be forced through a valve in the tank which regulates the flow of material.
Various lid structures have been used with such tanks in the past including lids with threads which engaged corresponding threads in the neck of the tank. To either remove or secure the lids, the lid had to be rotated relative to the tank. Such lid structures are not totally satisfactory particularly when the pressure in the tank was relatively high.